'school-supportive' originates from Modern English, specifically formed by combining the noun 'school' and the adjective 'supportive', where 'school' meant 'a place of learning' and 'supportive' meant 'providing encouragement or help'.

'school' comes from Old English 'scolu' (from Latin 'schola', from Greek 'scholē' originally meaning 'leisure' and later 'place of learning'); 'supportive' is formed from 'support' (Old French 'soutenir' from Latin 'supportare' meaning 'to carry from below' or 'to give support') plus the adjectival suffix '-ive'. The compound is a recent Modern English formation combining these elements.

The parts originally referred to 'place of learning' (school) and 'to carry from below/provide help' (support); over time these combined in Modern English to form the descriptive phrase meaning 'providing or showing support to schools or school-related activities'.